mirror of https://gitee.com/openkylin/linux.git
138 lines
3.8 KiB
C
138 lines
3.8 KiB
C
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/*
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* This file is included twice from vdso2c.c. It generates code for 32-bit
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* and 64-bit vDSOs. We need both for 64-bit builds, since 32-bit vDSOs
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* are built for 32-bit userspace.
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*/
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static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
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{
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int found_load = 0;
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unsigned long load_size = -1; /* Work around bogus warning */
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unsigned long data_size;
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Elf_Ehdr *hdr = (Elf_Ehdr *)addr;
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int i;
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unsigned long j;
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Elf_Shdr *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr,
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*alt_sec = NULL;
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Elf_Dyn *dyn = 0, *dyn_end = 0;
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const char *secstrings;
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uint64_t syms[NSYMS] = {};
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Elf_Phdr *pt = (Elf_Phdr *)(addr + hdr->e_phoff);
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/* Walk the segment table. */
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for (i = 0; i < hdr->e_phnum; i++) {
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if (pt[i].p_type == PT_LOAD) {
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if (found_load)
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fail("multiple PT_LOAD segs\n");
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if (pt[i].p_offset != 0 || pt[i].p_vaddr != 0)
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fail("PT_LOAD in wrong place\n");
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if (pt[i].p_memsz != pt[i].p_filesz)
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fail("cannot handle memsz != filesz\n");
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load_size = pt[i].p_memsz;
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found_load = 1;
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} else if (pt[i].p_type == PT_DYNAMIC) {
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dyn = addr + pt[i].p_offset;
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dyn_end = addr + pt[i].p_offset + pt[i].p_memsz;
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}
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}
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if (!found_load)
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fail("no PT_LOAD seg\n");
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data_size = (load_size + 4095) / 4096 * 4096;
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/* Walk the dynamic table */
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for (i = 0; dyn + i < dyn_end && dyn[i].d_tag != DT_NULL; i++) {
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if (dyn[i].d_tag == DT_REL || dyn[i].d_tag == DT_RELSZ ||
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dyn[i].d_tag == DT_RELENT || dyn[i].d_tag == DT_TEXTREL)
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fail("vdso image contains dynamic relocations\n");
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}
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/* Walk the section table */
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secstrings_hdr = addr + hdr->e_shoff + hdr->e_shentsize*hdr->e_shstrndx;
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secstrings = addr + secstrings_hdr->sh_offset;
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for (i = 0; i < hdr->e_shnum; i++) {
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Elf_Shdr *sh = addr + hdr->e_shoff + hdr->e_shentsize * i;
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if (sh->sh_type == SHT_SYMTAB)
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symtab_hdr = sh;
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if (!strcmp(secstrings + sh->sh_name, ".altinstructions"))
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alt_sec = sh;
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}
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if (!symtab_hdr) {
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fail("no symbol table\n");
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return 1;
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}
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strtab_hdr = addr + hdr->e_shoff +
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hdr->e_shentsize * symtab_hdr->sh_link;
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/* Walk the symbol table */
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for (i = 0; i < symtab_hdr->sh_size / symtab_hdr->sh_entsize; i++) {
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int k;
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Elf_Sym *sym = addr + symtab_hdr->sh_offset +
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symtab_hdr->sh_entsize * i;
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const char *name = addr + strtab_hdr->sh_offset + sym->st_name;
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for (k = 0; k < NSYMS; k++) {
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if (!strcmp(name, required_syms[k])) {
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if (syms[k]) {
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fail("duplicate symbol %s\n",
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required_syms[k]);
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}
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syms[k] = sym->st_value;
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}
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}
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}
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/* Remove sections. */
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hdr->e_shoff = 0;
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hdr->e_shentsize = 0;
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hdr->e_shnum = 0;
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hdr->e_shstrndx = SHN_UNDEF;
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if (!name) {
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fwrite(addr, load_size, 1, outfile);
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return 0;
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}
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fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
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fprintf(outfile, "#include <linux/linkage.h>\n");
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fprintf(outfile, "#include <asm/page_types.h>\n");
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fprintf(outfile, "#include <asm/vdso.h>\n");
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fprintf(outfile, "\n");
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fprintf(outfile,
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"static unsigned char raw_data[%lu] __page_aligned_data = {",
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data_size);
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for (j = 0; j < load_size; j++) {
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if (j % 10 == 0)
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fprintf(outfile, "\n\t");
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fprintf(outfile, "0x%02X, ", (int)((unsigned char *)addr)[j]);
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}
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fprintf(outfile, "\n};\n\n");
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fprintf(outfile, "static struct page *pages[%lu];\n\n",
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data_size / 4096);
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fprintf(outfile, "const struct vdso_image %s = {\n", name);
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fprintf(outfile, "\t.data = raw_data,\n");
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fprintf(outfile, "\t.size = %lu,\n", data_size);
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fprintf(outfile, "\t.pages = pages,\n");
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if (alt_sec) {
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fprintf(outfile, "\t.alt = %lu,\n",
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(unsigned long)alt_sec->sh_offset);
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fprintf(outfile, "\t.alt_len = %lu,\n",
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(unsigned long)alt_sec->sh_size);
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}
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for (i = 0; i < NSYMS; i++) {
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if (syms[i])
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fprintf(outfile, "\t.sym_%s = 0x%" PRIx64 ",\n",
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required_syms[i], syms[i]);
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}
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fprintf(outfile, "};\n");
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return 0;
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}
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